online to the bostonmarathontips, all one word, fbi.gov. let's get to the manhuntitself.jonathandietzis in new york. we're trying to figure out -- you know why i'm asking this, it's a speculation, right now at the command center, operating center, what is happening in terms of the filtering, archiving and catalog of calls coming in. we're told by pete williams that the fbi is receiving calls of suspected matchups with the faces here. >> they are getting some names and now what they are trying to do is run those names through data is bas and s databases and there is no name to match the suspects. but they are operating those lines. they have task force teams obviously ready to run out and follow any leads as they come in. some names are being offered from the calls and e-mails that are coming in but as of now there is no certain match and they are, again, using all their computers and technology to try to, as the names come in, to try to find them and find out which tips are more credible than the others. >> i'm wondering, jonathan, if you were in that crowd and survived and you're wa

. >>.>>jonathan, we'vegot the materials at hand which has been discovered, the pressure cooker, battery pack and circuit board and i didn't mention a piece of black nylon that was part of the bag. >> the best estimate that we have gotten is if they can track this to where they were sold and who purchased them, that's going to lead us to the suspect. we've seen this in previous investigations in the 1993 world trade center bombing. and as a result they caught the suspects m sa suspects. same theory here. that's part of the investigation and pouring all over the videotapes for leads and that one piece of videotape of a suspect putting down a bag outside the lord & taylor or caught on the lord & taylor surveillance tape is another. again, as pete williams and myself have been reporting all day, there is no suspect. there is no arrest. there is no specific name. now, we've been told that there have been several names out there that obviously they would want to run them down but we've been told that it's ruled out. the investigation is ongoing, moving forward. the piece of tape is one of many cri